In recent years, mobile phones are widely used for not only voice call but also packet communication. With the spread of packet communication in mobile phones, a flat rate model for fixing the packet communication fee has been introduced. For example, Non Patent Literature 1 discloses a pricing model for fixing the packet communication fee regardless of the packet communication volume. The adoption of the flat rate model allows the user to use packet communication without considering the fees, thus promoting the use of network services.
The flat rate model allows all the users to equally use a bandwidth, but may allow a small number of users to occupy the bandwidth by transmitting and receiving a large amount of data. In light of this, communication service carriers for mobile phones apply bandwidth limiting measures to the users performing a large amount of packet communication to prevent bandwidth oligopoly by a part of users.